For generating report i created the data source of type Extract. The column name Create Date, which is showing the abnormality, at the beginning of project column is of String data type(at Oracle and Tableau data source), and i used calculated field to extract date from a given string of column Create Date .Later the column at oracle database has changed from string to Date.
I changed the Tableau connection type Live , I am using the step Date-> Connection String(name)->Refresh, date(data from database) is visible at that column, if I change the column datatype from string to Date/Date Time error is throwing .
Now if i create a new project from scratch with same table ,column , no error is showing at that column (Create Date)with the same date(data from database) .
Please provide solution so that i can use my old data source, because i have created many dashboard on that datasource ,contains many calculated fields .